This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2000-165432, filed Jun. 2, 2000, the entire contents of which are incorporated herein by reference.
The present invention relates to a semiconductor processing system, and more particularly to a structural improvement for connecting an additional functional section to a vacuum processing section for performing a semiconductor process. The term xe2x80x9csemiconductor processxe2x80x9d used herein includes various kinds of processes which are performed to manufacture a semiconductor device or a structure having wiring layers, electrodes, and the like to be connected to a semiconductor device, on a target substrate, such as a semiconductor wafer or an LCD substrate, by forming semiconductor layers, insulating layers, and conductive layers in predetermined patterns on the target substrate.
In a conventional typical semiconductor processing system, vacuum processing units are individually completed. In other words, a vacuum unit for performing a first processing step or steps is independent of a vacuum unit for performing a second processing step or steps. When a small number of wafers, such as trial products, which need a large number of processing steps are produced, a plurality of, for example, two vacuum processing units may be required. In this case, wafers that have been processed in a first vacuum processing unit are transferred to a second vacuum processing unit by a driverless cart. For this reason, the following problems occur.
Unless processing of all wafers is completed in the first vacuum processing unit, the wafers cannot be transferred to the second vacuum processing unit. In addition, the wafers that have been processed in the first vacuum processing unit must be transferred to the second vacuum processing unit by a driverless cart. Therefore, it takes a long period of time to perform the predetermine processing for all wafers. Particularly, in the case of producing a small number of semiconductors, such as trial products, since a large number of steps are required, the work efficiency as a whole is lowered.
Further, it takes a relatively long period of time to transfer wafers between the first and second vacuum processing units by a driverless cart. During this period, if the wafers under processing are left in the first vacuum processing unit for a long time, the wafers may become contaminated or oxidized. Furthermore, since the driverless cart must be maintained and inspected periodically, it requires a considerable cost including an initial investment.
Based on the above conventional art, International Application WO 00/30135 discloses a semiconductor processing system, in which atmosphere-side transfer chambers of first and second vacuum processing units are connected to each other. In this semiconductor processing system, a transfer robot common to the first and second vacuum processing units is moved between the atmosphere-side chambers of both processing units. The transfer robot moves along rails laid in the atmosphere-side chambers to transfer a wafer between the first and second vacuum processing units.
In the above semiconductor processing system, various problems occur in the connecting portion between the atmosphere-side transfer chambers of the first and second vacuum processing units. Firstly, the atmosphere-side transfer chambers tend to cause a displacement at the connecting portion due to an error that may occur in fabrication, or any load that may be applied to the chambers after they are connected. Secondly, even if the connecting ends of the casings of the atmosphere-side transfer chambers are aligned with each other, the connecting ends of the rails inside the chambers may be displaced. If such a problem occurs, the transfer robot cannot be moved smoothly along the rails but may be vibrated. In this case, particles may be generated, or the wafer may be out of position or even dropped from the robot. Further, if the airtightness of the atmospheric transfer chambers is impaired, the wafer may be contaminated while it is transferred between the atmosphere-side transfer chambers of the first and second vacuum processing units.
An object of the present invention is to provide a semiconductor processing system in which a target substrate is smoothly transferred by a common transfer robot between two transfer chambers connected to each other.
Another object of the present invention is to provide a semiconductor processing system in which a target substrate is protected from dust or contamination, when it is transferred by a common transfer robot between two transfer chambers connected to each other.
According to a first aspect of the present invention, there is provided a semiconductor processing system comprising:
a first transfer chamber including a first casing having a plurality of ports which allow passage of a target substrate;
a first vacuum processing section connected to the first transfer chamber and having a first vacuum processing chamber configured to process the substrate in a vacuum atmosphere;
a first load port device, connected to the first transfer chamber, and configured to assist transfer of the substrate between the semiconductor processing system and a position outside the system;
a second transfer chamber detachably connected to the first transfer chamber and including a second casing having a plurality of ports which allow passage of the substrate, the second transfer chamber containing an internal atmosphere substantially in common with the first transfer chamber;
an additional functional section connected to the second transfer chamber, the additional functional section being selected from the group consisting of a second vacuum processing section and a second load port device, the second vacuum processing section having a second vacuum processing chamber configured to process the substrate in the vacuum atmosphere, and the second load port device being configured to assist transfer of the substrate between the semiconductor processing system and a position outside the system;
a transfer robot configured to transfer the substrate in the first and second transfer chambers;
first and second rails, respectively attached to the first and second casings in the first and second transfer chambers, and configured to form a track on which the transfer robot travels, the first and second rails constituting in association a horizontal rail integrally extending over the first and second transfer chambers;
a connecting and fixing mechanism configured to connect and fix the first and second casings to each other; and
first and second base plates respectively attached to the first and second casings and respectively supporting the first and second rails, a connecting position of the first and second rails and a connecting position of the first and second base plates being out of alignment with each other in a longitudinal direction of the horizontal rail.
According to a second aspect of the present invention, there is provided a semiconductor processing system comprising:
a first transfer chamber including a first casing having a plurality of ports which allow passage of a target substrate;
a first vacuum processing section connected to the first transfer chamber and having a first vacuum processing chamber configured to process the substrate in a vacuum atmosphere;
a first load port device, connected to the first transfer chamber, and configured to assist transfer of the substrate between the semiconductor processing system and a position outside the system;
a second transfer chamber detachably connected to the first transfer chamber and including a second casing having a plurality of ports which allow passage of the substrate, the second transfer chamber containing an internal atmosphere substantially in common with the first transfer chamber;
an additional functional section connected to the second transfer chamber, the additional functional section being selected from the group consisting of a second vacuum processing section and a second load port device, the second vacuum processing section having a second vacuum processing chamber configured to process the substrate in the vacuum atmosphere, and the second load port device being configured to assist transfer of the substrate between the semiconductor processing system and a position outside the system;
a transfer robot configured to transfer the substrate in the first and second transfer chambers;
first and second rails, respectively attached to the first and second casings in the first and second transfer chambers, and configured to form a track on which the transfer robot travels, the first and second rails constituting in association a horizontal rail integrally extending over the first and second transfer chambers;
a connecting and fixing mechanism configured to connect and fix the first and second casings to each other; and
a rail adjusting mechanism, interposed between the second casing and the second rail, and configured to adjust a position of the second rail relative to the second casing in a horizontal direction and a vertical direction substantially perpendicular to the longitudinal direction of the horizontal rail in order to obtain linearity of the horizontal rail between the first and second rails.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.